Water column nitrate+nitrite d15N measurements from R/V L'Atalante in the southwest Pacific Ocean between New Caledonia and Tahiti from February to March 2015

<p>This data set includes water column nitrate+nitrite d15N measurements. These measurements were used together with measurements of the d15N of particulate nitrogen collected in floating sediment traps that were deployed for several days to calculate the relative contribution of subsurface nitrate and nitrogen from N2 fixation for supporting export production (“d15N budgets”). The results suggest that N2 fixation supported a majority of export at Long Duration (LD) stations A and B, and a minor fraction of export at LD C. The results at LD stations A and B are unique compared to other d15N budgets from the oligotrophic regions, whereas the results from LD C are similar to prior reports from the eastern tropical South Pacific as well as the North Pacific near Hawaii. Additionally, these data are compared with other metrics of N2 fixation made on the same cruise.&nbsp;</p>

本数据集涵盖水柱硝酸盐与亚硝酸盐的δ¹⁵N（d15N）测量数据。此类测量数据与部署时长为数天的漂浮式沉积物捕集器采集的颗粒态氮δ¹⁵N测量数据结合使用，以计算支撑输出生产力的次表层硝酸盐氮与生物固氮（N2 fixation）来源氮的相对贡献，即“δ¹⁵N收支（"d15N budgets"）”。研究结果表明，在长期观测（Long Duration, LD）站位A与B，生物固氮支撑了大部分输出生产力；而在LD站位C，其贡献占比相对较小。相较于寡营养海域的其他δ¹⁵N收支研究结果，LD站位A与B的研究结果具有独特性；而LD站位C的结果则与东热带南太平洋以及夏威夷附近北太平洋的既往研究报道结果一致。此外，本数据集还与同一航次获取的其他生物固氮相关指标进行了对比分析。